Swimmers at a New Zealand beach had killer whales for playmates yesterday.

A video of an orca a few metres from swimmers at Hahei Beach on the Coromandel Peninsula is on social media and is getting picked up by local and international media.

About four orca visited nearby Hot Water Beach about 1pm, Gary Hinds, chairman of the Hot Water Beach Lifeguard service told NZ Newswire.

It's the first weekend New Zealand beaches are being manned by surf patrols, and about 350 people were on Hot Water Beach.

"They came in very close, about 10 metres from shore," he said.

It's a sight locals see about once to twice a season.

"They come in to feed on stingrays and stuff like that," Mr Hinds said.

"Some people don't see them, but the ones who do are in awe of seeing these orcas so close into the shore."

Surf lifesavers kept an eye on the situation to ensure people kept a safe distance and didn't get into trouble going out to look.

Orca are a toothed whale belonging to the dolphin family.

The Department of Conservation says orca can be identified relatively easily by distinctive black and white markings. They can grow up to nine metres in length, with male dorsal fins reaching higher than a metre.

They are acrobatic and are commonly seen breaching and flipper-slapping.